The invention relates to a closure device for a case of an antimagnetic material comprising a box part and a sliding lid, including at least one permanent magnetic locking pin slideable in the box part at right angles to the plane of the lid, loaded in the direction of the lid, this locking pin clasping behind a locking shoulder configured on the inner side of the sliding lid when closed.
One such closure device is known from French Pat. No. 2 086 962. This closure device can be opened only by personnel acquainted with its function by means of a permanent magnet or solenoid which is placed on the lid and magnetized in the opposite sense to that of the permanent magnetic locking pin. A case having this closure device is suitable for tamperproof security means e.g. for locks on locker or glass doors as well as instrument enclosures. Since the closure device requires no break-throughs in the case the case can be rendered waterproof or at least splashproof at minimum expense.
This known closure device has, however, the disadvantage that a normal sliding lid needs to be pulled over its full length from the box part to gain access to the security items, thus involving a relatively bulky installation.